An FDNY captain accused of trying to cover up the Staten Island firehouse brawl that left a firefighter’s face mangled was “very definitely involved” in the booze fest that led to the brawl, Fire Commissioner Nicholas Scoppetta said.

“Terrence Sweeney was very definitely involved, and that played an important part in imposing the severe punishment we imposed,” Scoppetta said in an interview that will air tomorrow on WNBC/Channel 4.

Capt. Sweeney was in charge of Ladder Co. 76 in Tottenville where a New Year’s Eve fight left firefighter Robert Walsh in a medically induced coma.

Sweeney avoided departmental charges last week by cutting a deal with the FDNY that includes a two-rank demotion back to firefighter – and a fine of more than $90,000. He was forced to retire this month.

Walsh’s nose was nearly ripped off and his eye sockets and jaw smashed in.

Fellow firefighter Michael Silvestri was charged with assault and harassment for bashing Walsh in the face with a metal folding chair.

‘Silvestri, who has been assigned to the Fire Department’s Bureau of Operations, was placed on restricted duty last week and put back on the payroll.